ABSTRACT

Amino acids found in two carbonaceous chondrites (C2) from Antarctica, namely the Yamato-793321 and the Belgica-7904, were at the level of sub-namo moles per gram sample. These quantities are very small for C2 chondrites. The carbon and nitrogen contents of these two meteorites were suitable for C2 chondrites and, therefore, those two chondrites were unusually depleted in amino acids. This finding is new and there are two plausible explanations for the depletion. One is low temperature and/or aqueous metamorphisms of the two meteorites on their parent bodies, and the other is leaching of water extractable portions of the two meteorites by Antarctic water.